Continuous positive airway pressure apparatus

ABSTRACT

A continuous positive airway pressure (CPAP) apparatus includes: a first unit including a first housing provided with a first flow path that connects a first inlet port and a first outlet port and in which an air blower is provided; and a second unit including a second housing provided with a second flow path that connects a second inlet port and a second outlet port. The first flow path between the first inlet port and the air blower includes a first silencer. The second flow path includes a second silencer. In a first use state where the second unit is attached to the first unit, the second outlet port is connected to the first inlet port. In a second use state where the second unit is not attached to the first unit, the first inlet port is opened to the outside.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of International Application No.PCT/JP2019/012775 filed on Mar. 26, 2019 which claims priority fromJapanese Patent Application No. 2018-067067 filed on Mar. 30, 2018. Thecontents of these applications are incorporated herein by reference intheir entireties.

TECHNICAL FIELD

The present disclosure relates to a continuous positive airway pressure(CPAP) apparatus that feeds air, which is suctioned into the apparatus,to a user's respiratory tract for therapy of sleep apnea syndrome.

BACKGROUND ART

It is considered that sleep apnea syndrome causing interruption ofbreathing during sleep results from physically narrowing of arespiratory tract serving as an airway. One of effective therapeuticmethods for sleep apnea syndrome is a method of therapy using a CPAPapparatus.

A CPAP apparatus serves to continuously feed air to a respiratory tractto open the respiratory tract in order to prevent apnea from occurringduring sleep. More specifically, the CPAP apparatus includes an airblower for feeding air, which is suctioned into the apparatus, throughan air tube to a mask put on a user's nose or mouth.

In this case, since the CPAP apparatus is used during bedtime and duringsleep, this CPAP apparatus is required to operate quietly. The causes ofdisturbing quietness are an operating noise, a wind noise and the likefrom a drive motor that are generated mainly when the above-mentionedair blower operates. If leakage of these noises to the outside of theapparatus can be suppressed, the quietness can be improved.

Thus, for example, Japanese Patent Laying-Open No. 2016-34411 (PTL 1)discloses a CPAP apparatus configured such that a suction-side silenceris provided between an air inlet port provided in an apparatus main bodyequipped with an air blower and this air blower, and a discharge-sidesilencer is provided between an air outlet port provided in theapparatus main body and a mask.

BRIEF SUMMARY

In addition to the above-mentioned quietness, the CPAP apparatus is alsostrongly required to be reduced in size and weight. This is because theCPAP apparatus has to be used continuously every day, which requires auser to carry this CPAP apparatus, for example, when the user stays outovernight and the like.

Also, a silencer provided for improving the above-mentioned quietness isgenerally enhanced in silencing effect in proportion to its volumeoccupied in the apparatus. Accordingly, the so-called trade-off relationlies between quietness and reduction in a size and a weight of theapparatus. This significantly hinders the improvement in convenience ofthe CPAP apparatus.

Thus, the present disclosure has been made in light of theabove-described problems, and one of the objects of the presentdisclosure is to provide a user-friendly CPAP apparatus that isexcellent in portability and quietness.

A CPAP apparatus according to the present disclosure feeds air suctionedinto the CPAP apparatus to a respiratory tract of a user. The CPAPapparatus includes a first unit and a second unit. The first unitincludes an air blower and a first housing in which the air blower ishoused. The second unit includes a second housing and is attachable toand detachable from the first unit. The first housing is provided with:a first inlet port through which air is introduced from outside thefirst housing; a first outlet port through which air is discharged frominside the first housing; and a first flow path in which the air bloweris provided and that connects the first inlet port and the first outletport. The second housing is provided with: a second inlet port throughwhich air is introduced from outside the second housing; a second outletport through which air is discharged from inside the second housing; anda second flow path that connects the second inlet port and the secondoutlet port. The first unit further includes a first silencer providedin a portion of the first flow path that is located between the firstinlet port and the air blower. The second unit further includes a secondsilencer provided in the second flow path. In a first use state wherethe CPAP apparatus is used in a state where the second unit is attachedto the first unit, the second outlet port is connected to the firstinlet port. In a second use state where the CPAP apparatus is used in astate where the second unit is not attached to the first unit, the firstinlet port is opened to outside.

In the CPAP apparatus according to the present disclosure, a volumeoccupying a portion functioning as the second silencer may be largerthan a volume occupying a portion functioning as the first silencer.

In the CPAP apparatus according to the present disclosure, the firstsilencer may include a wide portion and a narrow portion that aredisposed side by side in a direction in which the first flow pathextends. Furthermore, in the CPAP apparatus according to the presentdisclosure, the second silencer may include a resonant tube that isbranched from the second flow path.

In the CPAP apparatus according to the present disclosure, across-sectional area of the narrow portion that is orthogonal to an airflowing direction may be smaller than a cross-sectional area of the wideportion that is orthogonal to the air flowing direction, and the narrowportion may be disposed downstream from the wide portion in the airflowing direction.

In the CPAP apparatus according to the present disclosure, the firsthousing or the second housing may be provided with a gasket so as tosurround each of the first inlet port and the second outlet port in thefirst use state.

In the CPAP apparatus according to the present disclosure, the secondinlet port may be provided in a portion of the second housing that facesthe first housing at a distance from the first housing in the first usestate.

In the CPAP apparatus according to the present disclosure, the secondinlet port is disposed at an outer surface of the second housing, and aconcave portion is disposed at an outer surface of the first housing ata position facing the second inlet port, the concave portion beingrecessed from a surrounding area.

In an aspect of the CPAP apparatus according to the present disclosure,the second housing may be further provided with: a third inlet portthrough which air is introduced from outside the second housing; a thirdoutlet port through which air is discharged from inside the secondhousing; and a third flow path that connects the third inlet port andthe third outlet port. In this case, the second unit may further includea humidifying mechanism provided in the third flow path. In this case,it is preferable that the third inlet port is connected to the firstoutlet port in the first use state.

Furthermore, in the above-mentioned aspect, the first housing mayinclude a mounting surface located vertically on a lower side in thefirst use state, and a first connection surface provided with the firstinlet port and the first outlet port. The second housing may include abottom plate portion disposed vertically on a lower side in the firstuse state. Furthermore, the second silencer and the humidifyingmechanism may be disposed side by side in a horizontal direction on thebottom plate portion in the first use state. Also, the second housingmay include: a stage surface located vertically above the secondsilencer in the first use state; an upper surface located verticallyabove the humidifying mechanism and located higher than the stagesurface in the first use state; and a second connection surfaceconnecting the stage surface and the upper surface and provided with thesecond outlet port and the third inlet port. Furthermore, in this case,the second unit may be attached to the first unit such that the mountingsurface faces the stage surface and the first connection surface facesthe second connection surface, so as to connect the second outlet portto the first inlet port and to connect the third inlet port to the firstoutlet port.

In another aspect of the CPAP apparatus according to the presentdisclosure, the apparatus may further include a third unit that includesa third housing and that is attachable to and detachable from the firstunit. In this case, the third housing may be provided with: a thirdinlet port through which air is introduced from outside the thirdhousing; a third outlet port through which air is discharged from insidethe third housing; and a third flow path that connects the third inletport and the third outlet port. In this case, the third unit may furtherinclude a humidifying mechanism provided in the third flow path. In thiscase, the third inlet port may be connected to the first outlet port inthe first use state.

The present disclosure can provide a user-friendly CPAP apparatus thatis excellent in portability and quietness.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing the manner of attachment anddetachment of a main body unit to/from a base unit of a CPAP apparatusaccording to the first embodiment.

FIG. 2 is another perspective view of the manner of attachment anddetachment shown in FIG. 1 as seen from a different angle.

FIG. 3 is a perspective view showing the state where the main body unitis attached to the base unit in the CPAP apparatus according to thefirst embodiment.

FIGS. 4A and 4B are diagrams schematically showing the first use stateand the second use state of the CPAP apparatus according to the firstembodiment.

FIG. 5 is a diagram showing a functional block configuration in thefirst use state of the CPAP apparatus according to the first embodiment.

FIG. 6 is a diagram showing a functional block configuration in thesecond use state of the CPAP apparatus according to the firstembodiment.

FIG. 7 is a schematic cross-sectional view in the second use state ofthe CPAP apparatus according to the first embodiment.

FIG. 8 is a schematic cross-sectional view taken along a line VIII-VIIIshown in

FIG. 7.

FIG. 9 is a schematic cross-sectional view in the first use state of theCPAP apparatus according to the first embodiment.

FIG. 10 is a schematic cross-sectional view taken along a line X-X shownin FIG. 9.

FIG. 11 is a schematic cross-sectional view taken along a line XI-XIshown in FIG. 9.

FIG. 12 is a schematic cross-sectional view taken along a line XII-XIIshown in FIG. 9.

FIG. 13 is a perspective view showing the manner of attachment anddetachment of a main body unit, a base unit and an additional base unitof a CPAP apparatus according to the second embodiment.

FIG. 14 is a partially cutaway plan view showing the state where a mainbody unit is attached to a base unit in a CPAP apparatus according tothe third embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following, embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. In theembodiments described below, the same or common portions will be denotedby the same reference characters, and description thereof will not berepeated.

First Embodiment

FIG. 1 is a perspective view showing a manner of attachment anddetachment of a main body unit to/from a base unit of a CPAP apparatusaccording to the first embodiment of the present disclosure. FIG. 2 isanother perspective view of the manner of attachment and detachmentshown in FIG. 1 as seen from a different angle. FIG. 3 is a perspectiveview showing the state where the main body unit is attached to the baseunit in the CPAP apparatus according to the present embodiment. First,referring to FIGS. 1 to 3, an explanation will be given with regard to aschematic configuration of a CPAP apparatus 1A according to the presentembodiment and the manner of attachment and detachment thereof.

As shown in FIGS. 1 to 3, CPAP apparatus 1A includes a main body unit100 as the first unit, and a base unit 200 as the second unit. In thiscase, main body unit 100 mainly includes an air blower 140 and a firstsilencer 150 (see FIG. 5 to FIG. 9 and FIG. 12 and so on). Base unit 200mainly includes a second silencer 240 and a humidifying mechanism 250(see FIG. 5 and FIGS. 9 to 12 and so on).

Base unit 200 is attachable to and detachable from main body unit 100.In this case, CPAP apparatus 1A according to the present embodiment isconfigured to be usable in one of two states including the first usestate where base unit 200 is attached to main body unit 100; and thesecond use state where base unit 200 is not attached to main body unit100.

More specifically, in the first use state where CPAP apparatus 1A isused in the state where base unit 200 is attached to main body unit 100,both main body unit 100 and base unit 200 are used. In the second usestate where CPAP apparatus 1A is used in the state where base unit 200is not attached to main body unit 100, main body unit 100 is only used,and base unit 200 is not used.

This is because CPAP apparatus 1A has a configuration dividable into aplurality of units that are configured to be attachable to anddetachable from one another so as to be highly convenient not only whena user stays at home but also when the user stays out overnight. Inother words, during staying at home and the like, base unit 200 may beattached to main body unit 100, and thereby, CPAP apparatus 1A can beused in the above-mentioned first use state. During staying outovernight and the like, CPAP apparatus 1A can be used in theabove-mentioned second use state without having to attach base unit 200to main body unit 100.

Thus, although details will be described later, for example, duringstaying at home and the like, main body unit 100 having base unit 200attached thereto is used to thereby allow excellent quietness. On theother hand, for example, during staying out overnight and the like, baseunit 200 does not need to be carried but only main body unit 100 can becarried, thereby allowing excellent portability.

In this case, in CPAP apparatus 1A according to the present embodiment,a cutout portion that will be described later is provided at aprescribed position in base unit 200. Main body unit 100 is disposed soas to be fitted into this cutout portion, so that base unit 200 isattached to main body unit 100.

As shown in FIGS. 1 to 3, main body unit 100 has an approximatelyrectangular parallelepiped and flat outer shape, and has an outer casingformed of a first housing 110. First housing 110 has an upper surfaceand a lower surface that are arranged in the vertical direction in theuse state, and four side surfaces that connect the upper surface and thelower surface.

The upper surface of first housing 110 forms an operation surface 111 onwhich an operation unit 131 is provided. The lower surface of firsthousing 110 forms a mounting surface 112 that is placed on base unit 200in the first use state as described later and placed on a floor, a tableand the like in the second use state as described later. Furthermore,one of the four side surfaces of first housing 110 forms a firstconnection surface 113 that is connected to base unit 200 in the firstuse state. First connection surface 113 is orthogonal to mountingsurface 112.

As shown in FIGS. 1 to 3, base unit 200 has an approximately rectangularparallelepiped and elongated outer shape that has a portion providedwith a cutout portion in the longitudinal direction, and has an outercasing formed of a second housing 210. Second housing 210 has an uppersurface and a lower surface that are arranged in the vertical directionin the use state, and four side surfaces that connect the upper surfaceand the lower surface. The above-mentioned cutout portion is provided ata position on the upper surface side. Thereby, base unit 200 has astepped shape formed such that a step is provided on its upper surfaceside at one end portion in the longitudinal direction.

The lower surface of second housing 210 forms a mounting surface that isto be placed on a floor, a table and the like in the first use state. Aportion of the upper surface of second housing 210 that corresponds tothe above-mentioned cutout portion forms a stage surface 212 on whichmain body unit 100 is placed in the first use state. Also, a remainingportion of the upper surface of second housing 210 forms a tubeconnection surface 211 that is provided with a third outlet port 232 towhich an air tube 300 (see FIGS. 4A to 6 and the like) is connected inthe first use state. In this case, tube connection surface 211 is to belocated higher than stage surface 212 in the use state.

A portion included in the wall surface of second housing 210 thatcorresponds to the cutout portion and excluding stage surface 212 formsa second connection surface 213 that is connected to main body unit 100in the first use state. Second connection surface 213 is orthogonal tostage surface 212 and located to connect stage surface 212 and tubeconnection surface 211.

As shown in FIG. 1, first connection surface 113 of first housing 110 isprovided with a first inlet port 121 through which air is introducedfrom outside first housing 110, and a first outlet port 122 throughwhich air is discharged from inside first housing 110.

Also, as shown in FIGS. 1 and 2, stage surface 212 of second housing 210is provided with a second inlet port 221 through which air is introducedfrom outside second housing 210. As shown in FIG. 2, second connectionsurface 213 of second housing 210 is provided with a second outlet port222 through which air is discharged from inside second housing 210.

Also, as shown in FIGS. 1 and 2, second connection surface 213 of secondhousing 210 is provided with a third inlet port 231 through which air isintroduced from outside second housing 210. As shown in FIGS. 1 to 3,tube connection surface 211 of second housing 210 is provided with thirdoutlet port 232 through which air is discharged from inside secondhousing 210.

Thus, in the state where main body unit 100 is disposed in the cutoutportion provided in base unit 200 to thereby attach base unit 200 tomain body unit 100, mounting surface 112 of first housing 110 is locatedto face stage surface 212 of second housing 210 while first connectionsurface 113 of first housing 110 is located to face second connectionsurface 213 of second housing 210. Accordingly, first inlet port 121 andfirst outlet port 122 that are provided in first connection surface 113of first housing 110 are connected to second outlet port 222 and thirdinlet port 231, respectively, that are provided in second connectionsurface 213 of second housing 210. In this state where base unit 200 isattached to main body unit 100, CPAP apparatus 1A has an approximatelyrectangular parallelepiped outer shape as a whole. In other words, mainbody unit 100 has an outer shape that is approximately the same as theshape of the cutout portion.

On the other hand, in the state where base unit 200 is not attached tomain body unit 100, first connection surface 113 of first housing 110 isexposed to the outside. Thus, each of first inlet port 121 and firstoutlet port 122 provided in first connection surface 113 of firsthousing 110 is opened to the outside.

FIGS. 4A and 4B are diagrams schematically showing the use states of theCPAP apparatus according to the present embodiment. FIGS. 4A and 4B showthe first use state and the second use state, respectively. Thefollowing are explanations about the first use state and the second usestate of CPAP apparatus 1A according to the present embodiment withreference to this FIGS. 4A and 4B.

As shown in FIG. 4A, in the first use state, CPAP apparatus 1A is usedin the state where base unit 200 is attached to main body unit 100, asdescribed above. In this case, one end of air tube 300 is connected tothird outlet port 232 provided in base unit 200 while a mask 400 isconnected to the other end of air tube 300.

In the first use state, air blower 140 provided in main body unit 100 isdriven, and thereby, air is suctioned into CPAP apparatus 1A from secondinlet port 221 provided in base unit 200, and then, the suctioned air isdischarged from third outlet port 232 provided in base unit 200 to theoutside of CPAP apparatus 1A. Thereby, the air discharged from thirdoutlet port 232 is to be fed through air tube 300 and mask 400 into auser's respiratory tract.

As shown in FIG. 4B, in the second use state, CPAP apparatus 1A is usedin the state where base unit 200 is not attached to main body unit 100,as described above. In this case, one end of air tube 300 is connectedto first outlet port 122 provided in main body unit 100 while mask 400is connected to the other end of air tube 300.

In the second use state, air blower 140 provided in main body unit 100is driven, and thereby, air is suctioned into CPAP apparatus 1A fromfirst inlet port 121 provided in main body unit 100, and then, thesuctioned air is discharged from first outlet port 122 provided in mainbody unit 100 to the outside of CPAP apparatus 1A. Thereby, the airdischarged from first outlet port 122 is to be fed through air tube 300and mask 400 into the user's respiratory tract.

In this case, mask 400 is attached to the user so as to cover the user'snose or mouth, for example. Mask 400 having a suitable shape andstructure for the user can be selected from among various types ofmasks, and the shape and the structure shown in FIGS. 4A and 4B aremerely by way of example.

In addition, CPAP apparatus 1A serves to continuously feed air to theuser's respiratory tract to open the respiratory tract while adjustingthe timing of feeding air to the timing of the user's breathing in orderto prevent apnea from occurring during sleep. Accordingly, in CPAPapparatus 1A, in each of the first use state and the second use state, acontrol unit 130 performs various types of control such as feedbackcontrol and feedforward control, for example, based on the flow ratevalue, the pressure value and the like that are detected by a flow ratesensor 132 and a pressure sensor 133. Thereby, the rotation speed of airblower 140 is increased or decreased to adjust the air feeding amountand the like, so as to prevent apnea from occurring while the user issleeping.

FIG. 5 is a diagram showing a functional block configuration in thefirst use state of the CPAP apparatus according to the presentembodiment. FIG. 6 is a diagram showing a functional block configurationin the second use state of the CPAP apparatus. Then, referring to FIGS.5 and 6, the functional block configuration of CPAP apparatus 1Aaccording to the present embodiment will be hereinafter described.

As shown in FIGS. 5 and 6, CPAP apparatus 1A includes control unit 130,operation unit 131, flow rate sensor 132, pressure sensor 133, airblower 140, first silencer 150, second silencer 240, and humidifyingmechanism 250. Specifically, control unit 130, operation unit 131, flowrate sensor 132, pressure sensor 133, air blower 140, and first silencer150 are provided in main body unit 100 while second silencer 240 andhumidifying mechanism 250 are provided in base unit 200.

As shown in FIGS. 5 and 6, first housing 110 of main body unit 100 isprovided with a first flow path 120 in addition to first inlet port 121and first outlet port 122 as mentioned above. First flow path 120 isconfigured to connect first inlet port 121 and first outlet port 122.

Air blower 140 is provided in first flow path 120. Air blower 140 isformed of a centrifugal fan, for example. Air blower 140 is installed inan air blower chamber 117, as described later in association with FIGS.7 to 9 and FIG. 12, provided in first housing 110, and thus, disposed onfirst flow path 120.

In this case, air blower 140 has a casing 143 that is provided with anintake port 144 and a discharge port 145 of air blower 140. Thus, firstflow path 120 includes an upstream-side flow path portion 120A thatconnects first inlet port 121 provided in first housing 110 and intakeport 144 provided in air blower 140, and a downstream-side flow pathportion 120B that connects discharge port 145 provided in air blower 140and first outlet port 122 provided in first housing 110.

First silencer 150 is provided in upstream-side flow path portion 120Alocated between first inlet port 121 and intake port 144 in first flowpath 120. First silencer 150 serves to suppress leakage of a noiseoccurring in air blower 140 (an operation noise, a wind noise and thelike from a drive motor 142 as described later in association with FIGS.7 to 9 and FIG. 12, provided in air blower 140) to the outside throughfirst inlet port 121 in each of the first use state and the second usestate.

As shown in FIG. 5, second housing 210 of base unit 200 is provided witha second flow path 220 and a third flow path 230 in addition to secondinlet port 221, second outlet port 222, third inlet port 231, and thirdoutlet port 232 as mentioned above. Second flow path 220 is configuredto connect second inlet port 221 and second outlet port 222. Third flowpath 230 is configured to connect third inlet port 231 and third outletport 232.

Second silencer 240 is provided in second flow path 220. Second silencer240 serves to suppress leakage of the above-mentioned noise occurring inair blower 140 to the outside through second inlet port 221 in the firstuse state.

Humidifying mechanism 250 is provided in third flow path 230.Humidifying mechanism 250 serves to apply appropriate moisture to theair that is to be fed toward the user's respiratory tract in the firstuse state. Examples of applicable humidifying mechanism 250 may bevarious types of known humidifying devices such as a heating-typehumidifying device, an ultrasonic-type humidifying device, and anevaporation-type humidifying device. A heating-type humidifying devicecan be applied in the present embodiment. The humidifying mechanism isnot indispensable, and may not be provided as a matter of course.

Control unit 130 includes, as main components, a central processing unit(CPU) that executes a program, a read only memory (ROM)/random accessmemory (RAM), a drive unit that drives air blower 140, and the like. TheROM/RAM includes a ROM in which data is stored in a non-volatile manner,and a RAM in which data generated by the CPU executing the program anddata input through operation unit 131 are stored in a volatile manner.The components of control unit 130 are connected to one another by adata bus.

The process in the CPU is implemented by each hardware and softwareexecuted by the CPU. Such software is stored in the ROM/RAM in advance.Software also implements reception of the operation through operationunit 131, control of drive motor 142 to drive air blower 140, and thelike.

Control unit 130 is supplied with electric power by an internal powersupply (not shown) or an external power supply (not shown), andconnected to the external power supply, for example, through analternating-current (AC) adapter (not shown) and the like. Similar tocontrol unit 130, flow rate sensor 132 and pressure sensor 133 each arealso supplied with electric power by an internal power supply (notshown) or an external power supply (not shown). Flow rate sensor 132serves to measure the flow rate of air between CPAP apparatus 1A and airtube 300. Pressure sensor 133 serves to measure the pressure of air thatis supplied from air blower 140. Control unit 130 performs variouscontrols, such as feedback control and feedforward control, for example,based on the flow rate value, the pressure value and the like that aredetected by flow rate sensor 132 and pressure sensor 133, therebyincreasing or decreasing the rotation speed of air blower 140. In thecase where the above-mentioned internal power supply is provided, theinternal power supply is provided only in main body unit 100.

CPAP apparatus 1A may also be separately provided with a display unitincluding a liquid crystal display (LCD), an organicelectro-luminescence (EL) display, or the like. In this case, thedisplay unit may be provided in main body unit 100 or may be provided inbase unit 200. Furthermore, operation unit 131 does not necessarily needto be a button having a physical shape as shown in the figure, but maybe a touch panel or the like provided on the display surface of the LCD,for example. Buttons on operation unit 131 other than the button forswitching the power supply to be turned ON/OFF may be provided in baseunit 200. Such a configuration allows main body unit 100 to be furtherreduced in size and weight.

In this case, as shown in FIG. 5, in the first use state, first inletport 121 provided in first housing 110 is connected to second outletport 222 provided in second housing 210 while first outlet port 122provided in first housing 110 is connected to third inlet port 231provided in second housing 210. Thereby, in the first use state, secondflow path 220 is connected to the upstream side of first flow path 120while third flow path 230 is connected to the downstream side of firstflow path 120.

Accordingly, in the first use state, air blower 140 is driven to therebycause the air suctioned from second inlet port 221 to flow throughsecond flow path 220, first flow path 120 and third flow path 230sequentially in this order so as to be discharged from third outlet port232. The air discharged from third outlet port 232 is then fed throughair tube 300 and mask 400 into the user's respiratory tract. In otherwords, in the first use state, second inlet port 221 functions as an airintake port through which air is suctioned into CPAP apparatus 1A, andthird outlet port 232 functions as an exhaust port through which air isdischarged from inside CPAP apparatus 1A.

On the other hand, as shown in FIG. 6, in the second use state, firstinlet port 121 provided in first housing 110 is opened to the outside.

Thus, in the second use state, air blower 140 is driven to thereby causethe air suctioned from first inlet port 121 to be discharged from firstoutlet port 122 through first flow path 120. The air discharged fromfirst outlet port 122 is then fed through air tube 300 and mask 400 intothe user's respiratory tract. In other words, in the second use state,first inlet port 121 functions as an air intake port through which airis suctioned into CPAP apparatus 1A while first outlet port 122functions as an exhaust port through which air is discharged from insideCPAP apparatus 1A.

Accordingly, in the first use state, CPAP apparatus 1A is provided withsecond silencer 240 as compared with the second use state. Thus, notonly first silencer 150 but also second silencer 240 can function tosuppress leakage of the noise in air blower 140 through the air intakeport of CPAP apparatus 1A to the outside.

Furthermore, in the first use state, CPAP apparatus 1A is provided withhumidifying mechanism 250 as compared with the second use state. Thus,appropriate moisture can be applied to the air that is to be fed to theuser's respiratory tract.

On the other hand, in the second use state, CPAP apparatus 1A is notprovided with second silencer 240 and humidifying mechanism 250 ascompared with the first use state. Thus, CPAP apparatus 1A can beentirely reduced in size and weight, thereby allowing excellentportability.

In this way, first silencer 150 and second silencer 240 are locatedupstream from air blower 140 in the air flowing direction, so thatleakage of noise from first inlet port 121 or second inlet port 221 canbe reduced. Furthermore, as humidifying mechanism 250 is locateddownstream from air blower 140 in the air flowing direction in this way,highly humid air can be prevented from passing through air blower 140,and thereby, various electronic components including air blower 140 canbe prevented beforehand from being damaged by moisture.

FIG. 7 is a schematic cross-sectional view in the second use state ofthe CPAP apparatus according to the present embodiment. FIG. 8 is aschematic cross-sectional view taken along a line VIII-VIII shown inFIG. 7. The following is an explanation with reference to FIG. 7 andFIG. 8 about the detailed structure of main body unit 100 in CPAPapparatus 1A according to the present embodiment and the flow of airinside CPAP apparatus 1A in the second use state. In each of FIGS. 7 and8, the flow of air generated by the operation of air blower 140 isschematically shown by arrows.

As shown in FIGS. 7 and 8, the space inside first housing 110 of mainbody unit 100 is provided with various types of walls, hoses and thelike, and thereby partitioned into a plurality of chambers. Theplurality of chambers include a wide portion 115, a narrow portion 116,and air blower chamber 117. Such wide portion 115, narrow portion 116,and air blower chamber 117 correspond to upstream-side flow path portion120A as mentioned above.

Wide portion 115 is disposed adjacent to first inlet port 121 providedin first connection surface 113 of first housing 110. Thecross-sectional area of wide portion 115 that is orthogonal to the airflowing direction (i.e., the area of the cross section of wide portion115 that is taken along a line in parallel to the opening plane of firstinlet port 121) is formed relatively large so as to reduce the pressureloss that may occur in first inlet port 121. In addition, thecross-sectional area of wide portion 115 that is orthogonal to the airflowing direction is formed larger than the cross-sectional area ofnarrow portion 116 that is orthogonal to the air flowing direction.

In this case, first inlet port 121 is provided with a filter 170 throughwhich foreign substances such as dust contained in air are captured. Inorder to fix filter 170 to first connection surface 113, firstconnection surface 113 is equipped with a filter cover 171 that forms apart of first housing 110. Filter cover 171 is provided with a pluralityof holes arranged in rows and columns. The plurality of holes form firstinlet port 121.

Narrow portion 116 is disposed adjacent to wide portion 115. This narrowportion 116 is formed by providing a separation wall portion 114 insidefirst housing 110 and configured to have a relatively smallcross-sectional area that is orthogonal to the air flowing direction(the area of the cross section of narrow portion 116 that is taken alonga line in parallel to the opening plane of first inlet port 121). Thecross-sectional area of narrow portion 116 that is orthogonal to the airflowing direction is smaller than the cross-sectional area of theabove-mentioned wide portion 115 that is orthogonal to the air flowingdirection.

Air blower chamber 117 is disposed adjacent to narrow portion 116. Airblower 140 is housed inside air blower chamber 117. This air blowerchamber 117 is configured to have a relatively large cross-sectionalarea that is orthogonal to the air flowing direction (i.e., the area ofthe cross section of air blower chamber 117 that is taken along a linein parallel to the opening plane of first inlet port 121). Air blowerchamber 117 has a relatively large space that occupies most of firsthousing 110. The cross-sectional area of air blower chamber 117 that isorthogonal to the air flowing direction is larger than thecross-sectional area of narrow portion 116 that is orthogonal to the airflowing direction.

In this case, first flow path 120 corresponding to wide portion 115 andnarrow portion 116 is a section formed such that its cross-sectionalarea orthogonal to the air flowing direction is abruptly increased fromdownstream to upstream in the air flowing direction. This section is tofunction as first silencer 150 as mentioned above.

In other words, first silencer 150 is formed of a so-called muffler-typesilencer including wide portion 115 and narrow portion 116 that arearranged side by side in the direction in which first flow path 120extends. The cross-sectional area of narrow portion 116 that isorthogonal to the air flowing direction is smaller than thecross-sectional area of wide portion 115 that is orthogonal to the airflowing direction as described above. Also, narrow portion 116 isdisposed downstream from wide portion 115 in the air flowing direction.By the configuration as described above, the noise occurring in airblower 140 is attenuated as a result of irregular reflection or the likeof this noise passing through first silencer 150, with the result thatleakage of the noise through first inlet port 121 can be suppressed.

In addition, the cross-sectional area of narrow portion 116 that isorthogonal to the air flowing direction is suitably equal to or lessthan the half of the cross-sectional area of wide portion 115 that isorthogonal to the air flowing direction. This configuration caneffectively suppress leakage of the noise through first inlet port 121.

First silencer 150 having the above-mentioned configuration is effectiveat reducing the noise in a relatively high frequency band of about 1500Hz or more, but cannot necessarily sufficiently reduce the noise in thefrequency band lower than this relatively high frequency band. However,first silencer 150 having the above-mentioned configuration can bereduced in volume occupied inside first housing 110, and therefore,contribute to downsizing of main body unit 100.

Therefore, when not only reduction of the noise in a relatively highfrequency band is required, but also when reduction of the noise in alower frequency band is particularly required, for example, asound-absorbing member is further attached to the inner wall surface offirst housing 110 that forms upstream-side flow path portion 120A,thereby allowing reduction of the noise in a wider frequency band whileallowing downsizing of main body unit 100.

Air blower 140 is formed of a centrifugal fan, for example, and fixed toa wall portion that defines mounting surface 112 of first housing 110(i.e., a bottom plate portion) in the state where air blower 140 ishoused in air blower chamber 117. Air blower 140 includes an impeller141, a drive motor 142, and a casing 143.

Impeller 141 is fixed to the rotation shaft of drive motor 142. Thus,drive motor 142 is driven to thereby rotate impeller 141. Impeller 141is rotated to stir air to thereby apply centrifugal force to air, whichgenerates an airflow inside casing 143, with the result that air issuctioned from intake port 144 provided in casing 143, and dischargedfrom discharge port 145 provided in casing 143.

Intake port 144 of air blower 140 is provided in a portion of casing 143that is located above the shaft portion of impeller 141, and disposed toface the inner surface of the wall portion (i.e., a top plate portion)that defines operation surface 111 of first housing 110 at a distancefrom this inner surface. On the other hand, in a view seen along theshaft portion of impeller 141, discharge port 145 of air blower 140 isprovided in a portion of casing 143 that is tangent to the outer edge ofimpeller 141, and disposed at a prescribed distance from impeller 141.

In this case, intake port 144 of air blower 140 is in communication withair blower chamber 117. Also, discharge port 145 of air blower 140 isdisposed to cross air blower chamber 117 and has one end connected tothe other end of hose 160 connected to first outlet port 122 provided infirst housing 110. The space inside hose 160 corresponds todownstream-side flow path portion 120B as mentioned above.

First connection surface 113 of first housing 110 is provided with firstoutlet port 122. First outlet port 122 has a nozzle shape so as to allowair tube 300 connected thereto.

Thus, in the second use state, as described above, the air suctionedfrom first inlet port 121 is discharged from first outlet port 122through first flow path 120. More specifically, the air suctioned fromfirst inlet port 121 flows sequentially through wide portion 115, narrowportion 116, air blower chamber 117, air blower 140, and hose 160provided in first housing 110, and then, is discharged from first outletport 122.

FIG. 9 is a schematic cross-sectional view in the first use state of theCPAP apparatus according to the present embodiment. FIGS. 10, 11 and 12are schematic cross-sectional views taken along a line X-X, a line XI-XIand a line XII-XII, respectively, shown in FIG. 9. The following is anexplanation with reference to FIGS. 9 and 12 about the detailedstructure of base unit 200 in CPAP apparatus 1A according to the presentembodiment and the flow of air inside CPAP apparatus 1A in the first usestate. In each of FIGS. 9 to 12, the flow of air generated by theoperation of air blower 140 is schematically shown by arrows.

As shown in FIGS. 9 to 12, the space inside second housing 210 of baseunit 200 is partitioned into a first chamber 215 and a second chamber216 by a partition wall 214 provided in an approximately center portionof second housing 210 in the longitudinal direction. First chamber 215is provided as a space in the portion adjacent to main body unit 100(i.e., a space in the portion adjacent to main body unit 100 among aspace below main body unit 100 and a space located on the lateral sideof main body unit 100) in the state where base unit 200 is attached tomain body unit 100. Second chamber 216 is provided as a remaining space.

As shown in FIGS. 9 and 11, a wall portion having a prescribed shape isprovided in the space inside first chamber 215, thereby providing secondflow path 220 and second silencer 240. Second flow path 220 is providedso as to connect second inlet port 221 provided in stage surface 212 ofsecond housing 210 to second outlet port 222 provided in secondconnection surface 213 of second housing 210. Second silencer 240 isformed of a resonant tube 241 that is branched from second flow path220.

Second flow path 220 extends along the circumferential wall of theportion that defines first chamber 215 of second housing 210. Resonanttube 241 is disposed near the center portion of first chamber 215 so asto be surrounded by second flow path 220. Resonant tube 241 is formed ofa flow path having a meandering shape.

This resonant tube 241 is also called a Helmholtz resonator or aresonator, and has a function to attenuate the noise in a prescribedfrequency band. In this case, the frequency band of the noise attenuatedby resonant tube 241 depends on the natural frequency of resonant tube241. Accordingly, for example, the length and the like of resonant tube241 are adjusted as appropriate, to thereby particularly allow reductionof the noise in a frequency band lower than about 1500 Hz (for example,around 400 Hz) that cannot be sufficiently reduced by theabove-mentioned first silencer 150.

Second silencer 240 having the above-mentioned configuration iseffective at reducing the noise in a specific frequency band asdescribed above, and therefore, cannot necessarily sufficiently reducethe noise in a frequency band other than the above-mentioned frequencyband. Accordingly, in the case where the noise in a wider frequency bandparticularly needs to be reduced, for example, a sound-absorbing membermay be further attached to the inner wall surface of second housing 210that forms second flow path 220.

In this case, as shown in FIG. 9, in the state where base unit 200 isattached to main body unit 100, mounting surface 112 of first housing110 and stage surface 212 of second housing 210 are disposed at aprescribed distance (for example, about 1.5 mm) from each other. Morespecifically, referring to FIG. 7, four corners of mounting surface 112of first housing 110 are provided with legs 112 a protruding downward.Legs 112 a come into contact with stage surface 212 of second housing210, thereby implementing the above-mentioned configuration.

Thereby, second inlet port 221 provided in stage surface 212 of baseunit 200 is located to face first housing 110 at a distance from firsthousing 110, and second inlet port 221 is not blocked by first housing110. Furthermore, second inlet port 221 is in communication with thespace outside CPAP apparatus 1A through the gap formed between firsthousing 110 and second housing 210.

Therefore, by the configuration as described above, air is suctionedfrom every direction toward stage surface 212 in the portion providedwith second inlet port 221, as shown in FIG. 10, thereby allowingefficient suction of air. Also, first housing 110 is located to facesecond inlet port 221, thereby allowing effective suppression of leakageof the noise through second inlet port 221 to the outside.

Furthermore, as shown in FIGS. 9 and 10 and FIGS. 1 and 2 mentionedabove, stage surface 212 of second housing 210 is provided with aconcave portion 212 a that is recessed from other portions of stagesurface 212. Concave portion 212 a is provided with second inlet port221. In other words, a portion of the outer surface of second housing210 that includes the position provided with second inlet port 221(i.e., a part of stage surface 212) is formed as concave portion 212 athat is recessed from the surrounding area.

By the configuration as described above, concave portion 212 a and theportion that is located close to second inlet port 221 of second flowpath 220 and that is in communication with concave portion 212 a areformed as a section in which its cross-sectional area orthogonal to theair flowing direction is abruptly increased from downstream to upstreamin the air flowing direction.

In other words, second inlet port 221 and concave portion 212 a that arearranged side by side in the direction in which second flow path 220extends constitute a so-called muffler-type silencer. Also, thecross-sectional area of second inlet port 221 that is orthogonal to theair flowing direction is formed smaller than the cross-sectional area ofconcave portion 212 a that is orthogonal to the air flowing direction.Second inlet port 221 is disposed downstream from concave portion 212 ain the air flowing direction. Thus, similar to the above-mentioned firstsilencer 150, the above-mentioned section is also effective at reducinga noise, and consequently, can suppress leakage of the noise from CPAPapparatus 1A.

It should be noted that the cross-sectional area of second inlet port221 that is orthogonal to the air flowing direction is suitably equal toor less than the half of the cross-sectional area of concave portion 212a that is orthogonal to the air flowing direction. This configurationcan effectively suppress leakage of the noise through second inlet port221.

The above-mentioned concave portion does not necessarily need to beprovided in stage surface 212 of second housing 210, but may be providedin the portion of the outer surface of first housing 110 that includes aposition that faces second inlet port 221 (i.e., a part of mountingsurface 112) or may be provided in both stage surface 212 and mountingsurface 112.

On the other hand, as shown in FIGS. 9 and 12, in the state where baseunit 200 is attached to main body unit 100, first connection surface 113of first housing 110 and second connection surface 213 of second housing210 are disposed to face each other. Thereby, first inlet port 121provided in first connection surface 113 is connected to second outletport 222 provided in second connection surface 213 while first outletport 122 provided in first connection surface 113 is connected to thirdinlet port 231 provided in second connection surface 213.

In this case, as shown in FIG. 2 mentioned above, second connectionsurface 213 of second housing 210 is provided with a gasket 217 so as tosurround second outlet port 222. In the state where base unit 200 isattached to main body unit 100, gasket 217 is compressed by firsthousing 110 and second housing 210 so as to come into close contact withfirst housing 110 and second housing 210.

By the configuration as described above, in the first use state wherethe CPAP apparatus is used in the state where base unit 200 is attachedto main body unit 100, gasket 217 compressed to surround first inletport 121 and second outlet port 222 is disposed. This can preventleakage of air through the connection portion between second outlet port222 and first inlet port 121, and also can suppress leakage of noisethrough this connection portion to the outside.

Furthermore, second connection surface 213 of second housing 210 isprovided with a gasket 218 so as to surround third inlet port 231. Inthe state where base unit 200 is attached to main body unit 100, gasket218 is compressed by first housing 110 and second housing 210 so as tocome into close contact with first housing 110 and second housing 210.

By the configuration as described above, in the first use state wherethe CPAP apparatus is used in the state where base unit 200 is attachedto main body unit 100, gasket 218 compressed so as to surround firstoutlet port 122 and third inlet port 231 is disposed. This can preventleakage of air through the connection portion between first outlet port122 and third inlet port 231, and also can suppress leakage of noisethrough this connection portion to the outside.

The above-mentioned gasket does not necessarily need to be provided onsecond connection surface 213 of second housing 210, but may be providedon first connection surface 113 of first housing 110. In this case, itis preferable to provide the gasket so as to surround each of firstinlet port 121 and first outlet port 122.

As shown in FIGS. 9 to 12, third flow path 230 and humidifying mechanism250 are provided in the space inside second chamber 216. Third flow path230 is provided so as to connect third inlet port 231 provided in secondconnection surface 213 of second housing 210 to third outlet port 232provided in tube connection surface 211 of second housing 210.Humidifying mechanism 250 is placed on third flow path 230.

In this case, third flow path 230 is separated by the above-mentionedpartition wall 214 from second flow path 220. Humidifying mechanism 250is also separated by the above-mentioned partition wall 214 from secondsilencer 240. In other words, second silencer 240 and humidifyingmechanism 250 are disposed side by side in the horizontal direction onthe bottom plate portion that forms the mounting surface of secondhousing 210.

Humidifying mechanism 250 includes a tank 251 that stores water 253, anda so-called heating-type humidifying device formed of a heater and thelike (not shown). Tank 251 can be attached to second housing 210 in anattachable and detachable manner. When water 253 is consumed and thewater storage amount decreases, tank 251 can be detached from secondhousing 210, and filled with water 253, and then again attached tosecond housing 210.

The upper portion of tank 251 is provided with an inflow path 252through which air introduced into second housing 210 is guided. Thereby,the air introduced into second housing 210 through third inlet port 231provided in second connection surface 213 of second housing 210 flowsthrough inflow path 252 into the upper space of water 253 stored in tank251. When the air flows through the space, steam generated inhumidifying mechanism 250 is applied to the air. The space and inflowpath 252 correspond to third flow path 230.

As shown in FIG. 9, the wall portion (i.e., the top plate portion) thatforms tube connection surface 211 of second housing 210 is provided withthird outlet port 232. Third outlet port 232 has a nozzle shape so as toallow air tube 300 to be connected thereto.

Thus, in the first use state, the air suctioned from second inlet port221 flows through second flow path 220, first flow path 120, and thirdflow path 230 sequentially in this order so as to be discharged fromthird outlet port 232, as described above. More specifically, the airsuctioned from second inlet port 221 first flows through second flowpath 220 provided in first chamber 215 of second housing 210, then flowsthrough first flow path 120 that is formed of wide portion 115, narrowportion 116, air blower chamber 117, air blower 140, and hose 160provided in first housing 110, and further flows through third flow path230 provided in second chamber 216 of second housing 210 so as to bedischarged from third outlet port 232.

In CPAP apparatus 1A according to the present embodiment as describedabove, the above-mentioned configuration is provided to allow two typesof use states including: the first use state where CPAP apparatus 1A isused in the state where main body unit 100 is attached to base unit 200;and the second use state where CPAP apparatus 1A is used in the statewhere main body unit 100 is not attached to base unit 200, as repeatedlystated above.

Thus, for example, during staying at home and the like, CPAP apparatus1A is used in the state where base unit 200 is attached to main bodyunit 100 to thereby allow high quietness. On the other hand, forexample, during staying out overnight and the like, base unit 200 doesnot have to be carried but only main body unit 100 needs to be carried,thereby allowing high portability.

In this case, second silencer 240 provided in base unit 200 is greaterin volume occupied in CPAP apparatus 1A than first silencer 150 providedin main body unit 100. In general, a silencer is improved in silencingeffect in the entire frequency band in proportion to its occupyingvolume. Thus, as the occupying volume of second silencer 240 is larger,second silencer 240 can achieve a higher silencing effect, but theapparatus is increased in size accordingly.

However, as described above, second silencer 240 is provided not in mainbody unit 100 but in base unit 200. Thereby, during staying outovernight and the like, CPAP apparatus 1A can be used in theabove-mentioned second use state during bedtime and during sleep whilecarrying main body unit 100 but not carrying base unit 200. Also, duringstaying at home and the like, CPAP apparatus 1A can be used in theabove-mentioned first use state during bedtime and during sleep in thestate where base unit 200 is attached to main body unit 100.

Therefore, a high silencing effect during staying at home and the likecan be achieved while improving the portability for staying outovernight and the like, thereby allowing a user-friendly CPAP apparatusthat can be highly convenient not only during staying at home and thelike but also during staying out overnight and the like.

Second Embodiment

FIG. 13 is a perspective view showing the manner of attachment anddetachment between a main body unit, a base unit, and an additional baseunit of a CPAP apparatus according to the second embodiment of thepresent disclosure. In the following, a CPAP apparatus 1B according tothe second embodiment will be described with reference to FIG. 13.

As shown in FIG. 13, CPAP apparatus 1B includes a main body unit 100 asthe first unit, a base unit 200 as the second unit, and an additionalbase unit 500 as the third unit.

Main body unit 100 is the same as that in the above-mentioned firstembodiment. On the other hand, base unit 200 is different from that inthe above-mentioned first embodiment and mainly includes second flowpath 220 and second silencer 240, but does not include third flow path230 and humidifying mechanism 250. Furthermore, additional base unit 500mainly has a third flow path 530 and a humidifying mechanism 550.

In other words, CPAP apparatus 1B according to the present embodiment isconfigured of two units (i.e., base unit 200 and additional base unit500 in the present embodiment) obtained by dividing base unit 200 inCPAP apparatus 1A according to the first embodiment by theabove-mentioned partition wall 214. The configuration other than theabove is basically the same as that of CPAP apparatus 1A according tothe above-described first embodiment.

Base unit 200 is attachable to and detachable from main body unit 100.Furthermore, additional base unit 500 is also attachable to anddetachable from main body unit 100. In this case, CPAP apparatus 1Baccording to the present embodiment is configured to be usable in thefollowing four states including: the state where both base unit 200 andadditional base unit 500 are attached to main body unit 100; the statewhere base unit 200 is attached to main body unit 100, but additionalbase unit 500 is not attached to main body unit 100; the state whereadditional base unit 500 is attached to main body unit 100, but baseunit 200 is not attached to main body unit 100; and the state where bothbase unit 200 and the additional base unit are not attached to main bodyunit 100.

Second housing 210 of base unit 200 has stage surface 212 provided withsecond inlet port 221 and second connection surface 213 provided withsecond outlet port 222. Also, a third housing 510 of additional baseunit 500 has a third connection surface 513 provided with a third inletport 531, and a tube connection surface 511 provided with a third outletport 532.

Thereby, in the state where base unit 200 and additional base unit 500are attached to main body unit 100, mounting surface 112 of firsthousing 110 is located to face stage surface 212 of second housing 210while first connection surface 113 of first housing 110 is located toface second connection surface 213 of second housing 210 and thirdconnection surface 513 of third housing 510. Accordingly, first inletport 121 and first outlet port 122 provided in first connection surface113 of first housing 110 are to be respectively connected to secondoutlet port 222 provided in second connection surface 213 of secondhousing 210 and third inlet port 231 provided in third connectionsurface 513 of third housing 510.

On the other hand, in the state where base unit 200 is attached to mainbody unit 100 but additional base unit 500 is not attached to main bodyunit 100, mounting surface 112 of first housing 110 is located to facestage surface 212 of second housing 210 while first connection surface113 of first housing 110 is located to face second connection surface213 of second housing 210. Accordingly, first inlet port 121 provided infirst connection surface 113 of first housing 110 is to be connected tosecond outlet port 222 provided in second connection surface 213 ofsecond housing 210.

On the other hand, in the state where additional base unit 500 isattached to main body unit 100 but base unit 200 is not attached to mainbody unit 100, first connection surface 113 of first housing 110 islocated to face third connection surface 513 of third housing 510.Accordingly, first outlet port 122 provided in first connection surface113 of first housing 110 is to be connected to third inlet port 531provided in third connection surface 513 of third housing 510.

Furthermore, in the state where base unit 200 and additional base unit500 are not attached to main body unit 100, first connection surface 113of first housing 110 is exposed to the outside. Thus, each of firstinlet port 121 and first outlet port 122 that are provided in firstconnection surface 113 of first housing 110 is opened to the outside.

In addition to the first use state and the second use state as describedabove, the configuration as described above allows implementation of:the third use state where the CPAP apparatus is used in the state wherebase unit 200 is attached to main body unit 100, but additional baseunit 500 is not attached to main body unit 100; and the fourth use statewhere the CPAP apparatus is used in the state where additional base unit500 is attached to main body unit 100 but base unit 200 is not attachedto main body unit 100. Accordingly, in the third use state, secondsilencer 240 is added to thereby improve the silencing effect. In thefourth use state, humidifying mechanism 250 is added, so that moisturecan be added to the air that is to be fed into a respiratory tract.

Therefore, by CPAP apparatus 1B according to the present embodiment, theeffects described in the above first embodiment can be achieved, andadditionally, the apparatus can be used in the use state arbitrarilyselected from among the above-mentioned four use states, with the resultthat a further user-friendly CPAP apparatus can be provided.

Third Embodiment

FIG. 14 is a partially cutaway plan view showing the state where a mainbody unit is attached to a base unit in a CPAP apparatus according tothe third embodiment of the present disclosure. In the following, a CPAPapparatus 1C according to the present embodiment will be described withreference to FIG. 14.

As shown in FIG. 14, CPAP apparatus 1C has basically the sameconfiguration as that in the above-described first embodiment, andincludes main body unit 100 as the first unit and base unit 200 as thesecond unit. Main body unit 100 includes air blower 140 and firstsilencer 150. Base unit 200 includes a second silencer (that is the sameas second silencer 240 shown in FIG. 11 and the like) and a humidifyingmechanism (that is the same as humidifying mechanism 250 shown in FIG. 9and the like).

In this case, although no details will be explained for avoidingrepeated explanations, CPAP apparatus 1C according to the presentembodiment can also take two types of use states including: the firstuse state where CPAP apparatus 1C is used in the state where main bodyunit 100 is attached to base unit 200; and the second use state whereCPAP apparatus 1C is used in the state where main body unit 100 is notattached to base unit 200, as in the above-described first embodiment.One of these two types of use states can be selected when CPAP apparatus1C is used. Therefore, a user-friendly CPAP apparatus that is excellentin portability and quietness can be provided.

Furthermore, CPAP apparatus 1C according to the third embodiment allowsease of the operation of attaching and detaching base unit 200 to andfrom main body unit 100. In other words, in CPAP apparatus 1C, a firstmagnet 180 is provided in first connection surface 113 of first housing110 included in main body unit 100, and a second magnet 280 is providedin second connection surface 213 of second housing 210 included in baseunit 200. These first magnet 180 and second magnet 280 are attracted toand repelled from each other by the magnetic force, thereby allowingease of the above-mentioned attachment and detachment operations.

In this case, first magnet 180 and second magnet 280 each may be apermanent magnet or may be an electromagnet. In the case where one orboth of first magnet 180 and second magnet 280 is or are anelectromagnet, the electromagnet can be switched to be turned ON and OFFby a user interface such as a switch separately provided in CPAPapparatus 1C. In addition, first magnet 180 and second magnet 280 may bedisposed to face each other in the state where base unit 200 is attachedto main body unit 100, and may be located to be exposed from the surfaceof the housing or may be located inside the housing.

For example, in the case where first magnet 180 is formed of anelectromagnet while second magnet 280 is formed of a permanent magnet,the polarities of these magnets can be set so as to implement thefollowing manner of attachment and detachment.

Firstly, when base unit 200 is attached to main body unit 100, firstmagnet 180 formed of an electromagnet is switched to an OFF state.Thereby, first magnet 180 functions simply as a metal member (e.g., aferromagnetic body), and the magnetic force of second magnet 280generates force that acts in the attachment direction between firstmagnet 180 and second magnet 280.

On the other hand, when base unit 200 is detached from main body unit100, first magnet 180 formed of an electromagnet is switched to an ONstate. Thereby, first magnet 180 functions as a magnet, and repulsionoccurs between the magnetic force of first magnet 180 and the magneticforce of second magnet 280, thereby generating force that acts in thedetachment direction between first magnet 180 and second magnet 280.

Thereby, first magnet 180 and second magnet 280 act against each other,which generates attracting force or repelling force between main bodyunit 100 and base unit 200 in the attachment and detachment operation,thereby allowing ease of the mounting operation. Particularly in theattachment operation, the above-mentioned attracting force is causedonly by roughly aligning the projections and recesses provided in mainbody unit 100 with the projections and recesses provided in base unit200. This force allows accurate positioning of base unit 200 withrespect to main body unit 100, thereby allowing further ease of theattachment operation.

Furthermore, for example, in the case where first magnet 180 is formedof a permanent magnet and second magnet 280 is formed of anelectromagnet, the polarities of these magnets can be set so as toimplement the following manner of attachment and detachment.

Firstly, when base unit 200 is attached to main body unit 100, secondmagnet 280 formed of an electromagnet is switched to an OFF state.Thereby, second magnet 280 functions simply as a metal member (aferromagnetic body), and the magnetic force of first magnet 180generates force that acts in the attachment direction between firstmagnet 180 and second magnet 280.

On the other hand, when base unit 200 is detached from main body unit100, second magnet 280 formed of an electromagnet is switched to an ONstate. Thereby, second magnet 280 functions as a magnet, and repulsionoccurs between the magnetic force of second magnet 280 and the magneticforce of first magnet 180, thereby generating force that acts in thedetachment direction between first magnet 180 and second magnet 280.

Thereby, first magnet 180 and second magnet 280 act against each other,which generates attracting force or repelling force between main bodyunit 100 and base unit 200 in the attachment and detachment operation,thereby allowing ease of the mounting operation. Particularly in theattachment operation, the above-mentioned attracting force is causedonly by roughly aligning the projections and recesses provided in mainbody unit 100 with the projections and recesses provided in base unit200. This force allows accurate positioning of base unit 200 withrespect to main body unit 100, thereby allowing further ease of theattachment operation.

In this case, the positions in which first magnet 180 and second magnet280 are disposed are not limited to the positions as shown in FIG. 14,but may be positions as described below.

For example, first magnet 180 may be provided at or near first outletport 122 of first housing 110, and second magnet 280 may be provided ator near third inlet port 231 of second housing 210. In this case, firstmagnet 180 and second magnet 280 may be disposed annularly so as tosurround the flow path through which air flows in the attached state(i.e., first flow path 120 and third flow path 230). Further, in thiscase, a plurality of magnets obtained by dividing first magnet 180 andsecond magnet 280 may be arranged annularly. In the configuration asdescribed above, first outlet port 122 and third inlet port 231 areeasily aligned with each other particularly during attachment, andfurther, the sealing performance in the connection portion therebetweenis also improved.

Furthermore, for example, first magnet 180 may be provided at or nearfirst inlet port 121 of first housing 110, and second magnet 280 may beprovided at or near second outlet port 222 of second housing 210. Inthis case, first magnet 180 and second magnet 280 may be disposed in aframe shape so as to surround the flow path through which air flows inthe attached state (i.e. first flow path 120 and second flow path 220).Further, in this case, a plurality of magnets obtained by dividing firstmagnet 180 and second magnet 280 may be arranged in a frame shape. Inthe configuration as described above, first inlet port 121 and secondoutlet port 222 are easily aligned with each other particularly duringattachment, and further, the sealing performance in the connectionportion therebetween is also improved.

In addition, one of first magnet 180 and second magnet 280 mentionedabove may be replaced with an electromagnet or a permanent magnet so asto be formed of a metal member (a ferromagnetic body). Also, in such acase, the magnetic force acts to allow ease of the attachment operationand accurate positioning during this attachment operation. Also, in thedetachment operation, base unit 200 only needs to be detached from mainbody unit 100 against this magnetic force.

The above first to third embodiments of the present disclosure have beendescribed while exemplifying the case where a so-called muffler typesilencer formed of a wide portion and a narrow portion arranged side byside in the first flow path is applied as the first silencer provided inthe main body unit as the first unit, but the first silencer is notlimited thereto. The first silencer may be conventionally known varioustypes of silencers or may be a combination thereof. It should be notedthat a smaller-sized silencer is desirable in consideration of theportability for staying out overnight and the like.

Furthermore, the above first to third embodiments of the presentdisclosure have been described while exemplifying the case where asilencer configured to include a resonant tube is applied as the secondsilencer provided in the base unit as the second unit, but the secondsilencer is not limited thereto. The second silencer may beconventionally known various types of silencers or may be a combinationthereof.

It should be noted that the above-mentioned cross-sectional areas ofvarious types of flow paths and the like can be obtained from thecross-sectional image acquired by a computed tomography (CT) inspectionusing X rays, and the like, for example, without division or disassemblyof the CPAP apparatus itself. Furthermore, the cross-sectional area canalso be obtained, as a matter of course, by directly observing aplurality of portions obtained by dividing or disassembling the CPAPapparatus.

It should be understood that the embodiments disclosed herein areillustrative and non-restrictive in every respect. The technical scopeof the present disclosure is defined by the terms of the claims, and isintended to include any modifications within the meaning and scopeequivalent to the terms of the claims.

REFERENCE SIGNS LIST

1A, 1B, 1C CPAP apparatus, 100 main body unit, 110 first housing, 111operation surface, 112 mounting surface 112 a leg, 113 first connectionsurface, 114 separation wall, 115 wide portion, 116 narrow portion, 117air blower chamber, 120 first flow path, 120A upstream-side flow pathportion, 120B downstream-side flow path portion, 121 first inlet port,122 first outlet port, 130 control unit, 131 operation unit, 132 flowrate sensor, 133 pressure sensor, 140 air blower, 141 impeller, 142drive motor, 143 casing, 144 intake port, 145 discharge port, 150 firstsilencer, 160 hose, 170 filter, 171 filter cover, 180 first magnet, 200base unit, 210 second housing, 211 tube connection surface, 212 stagesurface 212 a concave portion, 213 second connection surface, 214partition wall, 215 first chamber, 216 second chamber, 217, 218 gasket,219 third connection surface, 220 second flow path, 221 second inletport, 222 second outlet port, 230 third flow path, 231 third inlet port,232 third outlet port, 240 second silencer, 241 resonant tube, 250humidifying mechanism, 251 tank, 252 inflow path, 253 water, 280 secondmagnet, 300 air tube, 400 mask, 500 additional base unit, 510 thirdhousing, 511 tube connection surface, 513 third connection surface, 530third flow path, 531 third inlet port, 532 third outlet port, 550humidifying mechanism.

1. A continuous positive airway pressure (CPAP) apparatus that feeds airsuctioned into the CPAP apparatus to a respiratory tract of a user, theCPAP apparatus comprising: a first unit including an air blower and afirst housing in which the air blower is housed; and a second unitincluding a second housing and being attachable to and detachable fromthe first unit, wherein the first housing comprises a first inlet portthrough which air is introduced from outside the first housing, a firstoutlet port through which air is discharged from inside the firsthousing, and a first flow path in which the air blower is provided andthat connects the first inlet port and the first outlet port, the secondhousing comprises a second inlet port through which air is introducedfrom outside the second housing, a second outlet port through which airis discharged from inside the second housing, and a second flow paththat connects the second inlet port and the second outlet port, thefirst unit further includes a first silencer provided in a portion ofthe first flow path that is located between the first inlet port and theair blower, the second unit further includes a second silencer providedin the second flow path, in a first use state of the CPAP apparatuswhere the second unit is attached to the first unit, the second outletport is connected to the first inlet port, and in a second use state ofthe CPAP apparatus where the second unit is not attached to the firstunit, the first inlet port is opened to outside.
 2. The CPAP apparatusaccording to claim 1, wherein a volume occupying a portion functioningas the second silencer is larger than a volume occupying a portionfunctioning as the first silencer.
 3. The CPAP apparatus according toclaim 1, wherein the first silencer includes a wider portion and anarrower portion that are disposed side by side in a direction in whichthe first flow path extends, and the second silencer includes a resonanttube that is branched from the second flow path.
 4. The CPAP apparatusaccording to claim 3, wherein a cross-sectional area of the narrowerportion that is orthogonal to an air flowing direction is smaller than across-sectional area of the wider portion that is orthogonal to the airflowing direction, and the narrow portion is disposed downstream fromthe wider portion in the air flowing direction.
 5. The CPAP apparatusaccording to claim 1, wherein the first housing or the second housing isprovided with a gasket so as to surround each of the first inlet portand the second outlet port in the first use state.
 6. The CPAP apparatusaccording to claim 1, wherein the second inlet port is provided in aportion of the second housing that faces the first housing at a distancefrom the first housing in the first use state.
 7. The CPAP apparatusaccording to claim 6, wherein the second inlet port is disposed at anouter surface of the second housing, and a concave portion is disposedat an outer surface of the first housing at a position faces the secondinlet port, the concave portion being recessed from a surrounding area.8. The CPAP apparatus according to claim 1, wherein the second housingfurther comprises a third inlet port through which air is introducedfrom outside the second housing, a third outlet port through which airis discharged from inside the second housing, and a third flow path thatconnects the third inlet port and the third outlet port, the second unitfurther includes a humidifying mechanism provided in the third flowpath, and the third inlet port is connected to the first outlet port inthe first use state.
 9. The CPAP apparatus according to claim 8, whereinthe first housing comprises a mounting surface located vertically on alower side in the first use state, and a first connection surfaceprovided with the first inlet port and the first outlet port, the secondhousing includes a bottom plate portion disposed vertically on a lowerside in the first use state, the second silencer and the humidifyingmechanism are disposed side by side in a horizontal direction on thebottom plate portion in the first use state, the second housingcomprises a stage surface located vertically above the second silencerin the first use state, an upper surface located vertically above thehumidifying mechanism and located higher than the stage surface in thefirst use state, and a second connection surface connecting the stagesurface and the upper surface and provided with the second outlet portand the third inlet port, and the second unit is attached to the firstunit such that the mounting surface faces the stage surface and thefirst connection surface faces the second connection surface, so as toconnect the second outlet port to the first inlet port and to connectthe third inlet port to the first outlet port.
 10. The CPAP apparatusaccording to claim 1, further comprising a third unit that includes athird housing and that is attachable to and detachable from the firstunit, wherein the third housing comprises a third inlet port throughwhich air is introduced from outside the third housing, a third outletport through which air is discharged from inside the third housing, anda third flow path that connects the third inlet port and the thirdoutlet port, the third unit further includes a humidifying mechanismprovided in the third flow path, and the third inlet port is connectedto the first outlet port in the first use state.